Heat exchangers



July 2, 1957 I R. JlPP I 2,797,498

' HEAT EXCHANGERS I Filed March 31, 1954 s Sheets-Sheet 1 Filed March51. 1954 R. JIPP HEAT EXCHANGERS I 5 Shets-Shaet? Inventor? 5Sheets-Sheet 3 o f. 0 o, v

R. JIPP H E AT EXCHANGERS July 2, 1957 Filed March 31, 1954 July 2, 1957JIPP 2,797,498

I HEAT EXCHANGERS Filed March 31, 1954 5 Sheets-Sheet 4 Inventor: I E?J/ PP R. JlPP HEAT EXCHANGERS July 2, 1957 5 Sheets-Sheet 5 Filed March31, 1954 A 2,797,498 Patented July 2, 1957 HEAT EXCHANGERS.

Rolf Jipp, Lubeclr-Travemunde, Germany, assignor to Maschinenfabrik BethAktiengesellschaft, Lubeck, Germany Application March 31, 1954, SerialNo. 420,168

. Claims priority, application Germany May 7, 1953 11 Claims. (Cl.34-164) The present invention relates to a heat exchanger, andparticularly to a heat exchanger forexchanging heat between a solidgranular material and a fluid.

It'is an object of the present invention to provide a I device of the'kind described which allows the heat exchange to be carried out undervacuum.

it is another object of the present invention to provide and dry solidgranular materials having :a range of grain 7 sizes between and 150millimeters.

In a preferred embodiment of the present invention several verticaltubes are arranged in a circle and several helical screw-shaped membersare arranged, respectively, in the vertical tubes, the material to betreated being consecutively fed by a revolving distributing device orthe like to the vertical tubes.

Other objects and advantages of the present invention will becomeapparent from the following detailed description thereof when read inconnection with the accompanying drawings showing, by way of example,some embodiments of the present invention. In the drawings Fig.1 is avertical section of a first embodiment of the present invention;

Fig. 2 is a cross section taken along the line AB shown in Fig. 1; i

Fig. 3' is a longitudinal section, partly in elevation, of

shaped pipe 8 is continued by a pipe 10 secured to a ringshaped member 9rotatable about the middle axis thereof and provided on the lower sidethereof with a toothed rim 11 engaging a pinion 13 driven by an electricmotor 12 carried by a projecting part 12 of the upper part 1'. of thecasing 1 connected therewith by flange-like parts in.

Within each of the vertical tubes 4 is arranged a vertical helicalscrew-shaped member 16 consisting of a plunality of sections such as 16,16", 16", etc. forming a series and being separated from one another bygaps such as 16a and 16b. The upper edge 160 of the uppermost section 16is horizontal as will be seen from Fig. 1. The helical screw-shapedmembers 16 are secured to carrying rods which are suspended by one-armedlevers 1'7 swingable about stationary members such as 17 and having freeends carrying rollers 18 being in contact with the upper surface of thering-shaped member 9 which is provided with one or more cams 19 forimparting to the rods 15 impact-like lifting and lowering movements. a

A connecting pipe 20 is provided in the upper part of the casing 1whereas another connecting pipe 22 is provided in the lower part of thecasing 1 and connected by I21 bend or elbow 2.3 to a connecting pipe 24connected to the pipe 7.

The chamber 2 enclosed by the casing 1 is provided with a plurality ofhorizontally arranged bafiies nor the like having edge portions such as21a and 2112 which are parallel to one another and turned downwards soas to impart a zigzag flow to the fluid flowing downwardsin the casingl. The upper part of the casing 1 is separated from the upper part i bya conical wall 1d. The upper part 1' of the casing 1 communicating withthe interiors of the tubes 4 is provided with an elbow piece 25 servingas an outflow for the gaseous components of the reactions.

a second embodiment of the present invention;

Fig. 4 is a cross section on an enlarged scale of a third embodiment ofthe present invention;

Fig. 5 is a side elevation, partly in section, of a slightly modifiedembodiment such as that shown in Fig. 3, in connection with someadditional devices;

Fig. 6 is a section of :a modified detail;

Fig 7 is a longitudinal section, partly. in elevation, of a furtherembodiment of the present invention; and

Fig. 8 is a plan view of the device shown in Fig. 7.

Referring now to the drawings and first to Figs. 1 and 2, the heatexchanger includes a casing 1. having a vertical axis 3 (Fig. 2) aboutwhich are concentrically arranged a plurality, for instance eightsubstantially vertical tubes 4 secured to an upper plate 5 and a lowerplate 6. The

plates 5 and 6 delimit a chamber. 2, forming the interior of the casing1 and containing the tubes 4. A pipe 7 is connected to the lower plate 6by a frusto-conical part 7 In the upper part 1 of the casing 1 above theupper plate 5 an elbow-shaped pipe 8 is arranged which revolves so as tocome into operative connection consecutively with the upper ends of thevertical tubes' i. The elbow- The operation of this device isas-follows:

The solid granular material is conveyed through the pipe 14' providedwith a conveying screw 14 to the en? trance of the pipe It). At the sametime the electric motor 12 is put into operation so that the ring-shapedmember 9 is rotated and imparts a rotation to the pipe 10 and theelbow-shaped pipe 8 connected thereto so that the latter delivers thegranular material to the upper ends of the tubes 4 one after the other.Furthermore the cam 19 lifts the rollers 18 of the one-armed levers 17one after the other, so that the rods 15 carrying thescrews 16 areimparted vertical oscillatory movements in substantially vertical Idirections. Thus the granular solid material conveyed by the screw 14and dropping down through the pipe 10 is supplied consecutively to thetubes 4'containing the screw-shaped members 16 undergoing a verticaloscillatory movement in the manner described hereinabove so that thegranular material will be conveyed downwards by the sections such as 16,16",16", etc. of the helical screweshaped members 16.

At the same time, a fluid such as preheated gas intended to dry thesolid granular materialis admitted by the connecting pipe 20 and isimparted a zigzag flow in the chamber 2 by the bafiies 21. .Afterflowing through the chamber Zthe gas flows through the connecting pipe22, the elbow 23, and the connecting pipe 24 into the pipe. 7 andupwards through thefrusto-conical part-7' closed at its upper end by thelower plate 6 into the tubes 4 which it traverses in upward direction soas to enter the upper part 1' of the casing 1 from which the gas isdischarged by the elbow piece 25. e

The solid granular material leavingthe screw-shaped members 16 and thetubes 4 enclosing the same are transported by the frusto-conical part7', and the pipe 7 in the direction of the arrow shown in full lines inFig. 1,

are supplied, if desired, to a sluice (not shown) or the like, and arefinally discharged. The path of the gas is indicated in Fig. 1 by thearrows shown in broken lines. It should be noted that the gas passesthrough the tubes 4 along screw-shaped paths imparted to the same by thescrew-shaped members 16. If desired, a fan (not shown) may be connectedto the elbow piece 25.

The screw-shaped paths through the tubes 4 cause the heat carrier (gas)to come into effective contact on a large surface and at a favorablyretarded rate with the granular solid material sliding downwards alongthe sections such as 16', 16", 16", etc. of the screw-shaped members 16.In consequence thereof, the gas yields the heat contained therein to thesolid material so as to evaporate or to volatilize the moisturecontained in the solid material and to preheat the same.

The quantity of the solid material may be controlled, if desired, bycontrolling the speed of the revolving movement of the ring-shapedmember 9 driving the pipe 10 by adjusting the speed of the electricmotor 12.

Furthermore the height of the projection or projections 19 of thering-shaped member 9 can be made adjustable by adjusting means (notshown) so as to adjust the amplitude of the movements of the helicalscrew'shaped members 16 with respect to the tubes 4.

Furthermore to the helical screw-shaped members 16 can be impartedinstead of an oscillatory movement a rotatory knocking movement.Furthermore the electric motor 12 may be provided with means such asresistors (not shown) for changing in stages the number of revolutionsthereof so that the number of movements, for instance verticaloscillatory movements of the helical screwshaped members 16 per unittime can be arbitrarily controlled.

Referring now to Fig. 3 of the drawings a dust chamber 31' is providedwith a ceiling 31 forming the bottom wall of a chamber 32" having acylindrical side wall portion 32 provided on its inner side with astructure 32' consisting of refractory stones. The ceiling 33 of thechamber 32' carries a plurality of vertical tubes 34 consistingpreferably of a ceramic material. The tubes 34 are provided withhelically screw-shaped members 35 carried by rods 36, respectively. Thescrew-shaped members 35 may be subdivided into sections, such as 16',16", etc. shown in Fig. l, and may be alternately lifted and lowered,and/ or rotated, the lifting and lowering movement being caused by rodssuch as 36 driven by the gearing 36', 36", the gear wheel 36" beingrigid with the pipe 37 connected to the elbow-shaped pipe 37corresponding to the pipe 10 and the elbow-shaped pipe 8 shown in Fig.l. The pipe 37' is connected to a screw conveyor 60 driven by anelectric motor 61 and conveying the solid granular material to the pipe37'. The gear wheel 36" is driven by a bevel gear 38' driven by theelectric motor 38. Below the lower ends of the tubes 34 and within thechamber 32' a funnel 39 is arranged which is preferably suspended bymembers such as 39" from the ceiling 33. The funnel 39 has an upperdiameter so that it catches any material subjected to a treatment withinthe tubes 34, and it discharges the same through a vertical tubeshapedpart 39 extending through an opening 42 in the bottom wall 31. Thematerial is conveyed by the part 39' to a chute 40 which supplies thesame to a rotating cylindrical kiln or the like.

The gas enters through an inlet (not shown) the dust chamber 31' fromwhich it escapes through the opening 42 in the ceiling 31 through whichthe part 39 extends without filling it. After. leaving the wide opening.42 the hot gases pass around the. funnel 39 and enter the pipes 34 inwhich they act upon the solid granular material such as raw powderedcement flowing downwards in counterflow. The gases leave the devicethrough the upper part 48 designed as a hollow ring-chamber and arrangedabove the pipes 34.

In the embodiment shown in Fig. 4 a metal part or casing 401 is providedon its inner wall with a heat insulation 402 which encloses sectorlikestructures 403 provided with internal hollows 404 forming verticaltubes. The hollows are the analogs of the tubes 34 shown in Fig. 3.

The structures shownin Figs. 3 and 4 allow an essential simplificationof the heat exchanger and a better supervision and inspection thereofdue to the insulation of the tubes against the casing, or, if the tubesare manufactured from ceramic material, or are built up separately fromfire-proof stones as shown in Fig. 4, due to the arrangement below thebottom of the heat exchanger of a collecting funnel as shown in Fig. 3,for passing on the treated material, and the provision adjacent to thefunnel of openings through which the treating fluids enter.

If such a heat exchanger is intended for the treatment of raw pulverizedcement in cement factories, the heat exchanger may be arranged, as shownin Fig. 5 of the drawings, immediately on the ceiling wall of a dustchamber thus decreasing essentially the overall height of the plant. InFig. 5 the heat exchanger is essentially de signed as in Fig. 3 andincludes the cylindrical lower portion 32, the tubes 34, the upper part43, and the pipe 37 which is connected in this case to a conicalintermediate part or separator 37" and a cyclone 47 more fully to bedescribed hereinafter. The heatexchanger stands on the floor 31 whichforms the ceiling of the dust chamber 31 and is provided with an opening42 through which the vertical tube-shaped part 39' of the funnel (notshown) extends. The part 39' leads the solid material over the chute 40to the rotating cylindrical kiln 41 or the like. The lower part of theheat exchanger including the lower portion 32 in which the funnel (notshown) is arranged consists preferably of ceramic material or is linedwith fire-proof bricks or stones.

In order to decrease the overall height of the heat exchanger and theparts connected thereto the supply bin or silo 45 containing the solidgranular material to be delivered to the heat exchanger is also arrangedon the floor 31 and connected with the heat exchanger by a device 52 forwithdrawing predetermined quantities of solid material from the storagebin 45, and a pneumatic conveying pipe 46 which conveys a mixture of airand solid material in the direction of the horizontal arrows M and N tothe cyclone 47 connected to the conical part or separator 37". The airis driven through the pipe 46 by a fan (not shown). From the cyclone 47the mixture of air and solid material enters into the conical part orseparator 37 in which the solid material is separated from the air whichis discharged at the upper end of the cyclone 47 in direction of thearrow 0. Preferably hot air is used as conveying air so that the solidmaterials withdrawn from the silo 45 are preheated while they passthrough the conveying pipe 46.

If desired, the tubes 4 shown in Figs. 1 and 2, and 34 shown in Figs. 3and 5, may have a non-circular cross section, for instance arectangular, square, or polygonal cross section. Furthermore the tubesmay be arranged in a plurality of concentric circles, squares, orpolygons.

Referring now to Fig. 6 of the drawings the tubes such as 634 containingthe helical screw-shaped members (not shown) are provided with one ormore short feed pipes or nipples such as 48, 49, 50, and 51, throughwhich a gaseous, liquid, or solid substance, or a combination of thesame may be conveyed and added to the solid material traveling throughthe tubes 634 from the top to the bottom. The materials passing throughthe feed pipes 48-51 and leaving the same in direction of the curvedarrows may be periodically changed, if desired, so that the solidmaterial passing through the tubes such as 634 is periodically subjectedto different treatments.

Referring now to Figs. 7 and 8 of the drawings, showing a modificationof the device shown in Fig. 1, a continuously variable transmissiongearing 100 of a design well known per se in the art, is arrangedbetween an electric motor (not shown) corresponding to the electricmotor 12 shown in Fig. 1, and a gear wheel 107 driving a toothed rim 111formed on the outside of a wheel 112 to be described more in detailhereinafter. The toothed rim 111 is connected to a part 109 which is inrigid connection with the pipe 110 forming the common upper part of theelbow-shaped pipes 108 and 108' arranged diametrically opposite to eachother.

The wheel 112 is made in one piece with a rim-like structure 113carrying on its outer perimeter a plurality of cams 105 engaging,respectively, the ends of levers 101 acted upon, respectively, bypressure springs 104 supported by preferably adjustable members 114 bythe adjustment of which the pressures can be changed which are exertedby the springs 104 on the levers 101. The latter are rigidly connected,respectively, with the shafts 102 of the helical screw-shaped members103 designed as multiple, for instance double screws.

The operation of this device is as follows:

When the toothed wheel 107 is rotated by the transmission gearing 100driven by the electric motor (not shown), the wheel 112 rotates and,therefore, the rimlike part 113 thereof carrying the cams 105 is rotatedin the direction of the arrow R shown in Fig. 8. During the rotation thecams 105, the number of which is somewhat lower than the number of thelevers 101, come into engagement with the latter. In the position shownin Fig. 8 the cam 105 is on the point of engaging the ballshaped head115 of one of the levers 101 Whereas the cam 105" has just passed underthe head 115 of the following lever 101. Thus it is seen that the leversone after the other are at first pressed backwards against the force ofthe springs 104 by the cams such as 105 until the rimlike part 113 hasmoved further so that the cam 105' comes into a position relative to thehead 115 which is shown in Fig. 8 for the cam 105" and the head 115'. Inconsequence thereof the lever 101 which had first moved in the directionof the arrow S thereby compressing the spring 104 is now moved in thedirection of the arrow T until the lever 101 collides with a stop member105. By this sudden change of direction of the movement of the levers101 the latter exert impulses on the shafts 102 of the helicalscrew-shaped members 103, respectively, and the energy transmitted tothe same causes the dry granular material to move downwards along theturns of the helices 103 towards the lower end (not shown) of thehelices. The latter are wound in a direction corresponding to thedirection in which the levers 101 strike the stop members 106. Theenergy of the strokes may be adjusted by adjusting the pressure exertedby the springs 104 as described hereinabove. In other respects theembodiment shown in Figs. 7 and 8 operates as that shown in Fig. 1.

It should be understood that numerous changes may be made in the form,construction, and arrangement of the several parts of the illustratedheat exchangers without departing from the spirit and scope of myinvention or sacrificing any of its attendant advantages, the heatexchangers herein described being merely for the purpose of illustratingthe invention.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is as follows:

1. A heat exchanger for exchanging heat between a solid granularmaterial and a fluid, comprising, in combination, a vertical casing, aplurality of substantially vertical tubes arranged in said casing, aplurality of helical screwshaped members supporting the solid granularmaterial and being arranged, respectively, vertically in said verticaltubes, an upper chamber substantially arranged above said vertical tubesand said screw-shaped members, a distributing device arranged in saidupper chamber, said distributing device including at least oneautomatically revolving part coming into operative connectionconsecutively with the upper ends of said vertical tubes and supplyingthe solid granular material successively to said helical screw-shapedmembers arranged in said vertical tubes and a lower chambersubstantially arranged below said vertical tubes and said screw-shapedmembers, said lower chamber collecting the solid granular materialpassing through said vertical tubes, an input duct for supplying fluidto the interior of said casing, the fluid entering the upper part ofsaid vertical casing, passing the interior of said vertical casingaround said vertical tubes, so as to enter said lower chamber, beingdistributed therein and passing into said vertical tubes in counterflowto the solid granular material, and an exhaust duct for removing saidfluid from said upper chamber, whereby the solid granular material issubjected to an eflective heat exchange with the fluid in said tubes,the fluid exhausts after leaving said vertical tubes via said upperchamber and said exhaust duct.

2. A heat exchanger as claimed in claim 1, and means for impartingmovements to said helical screw-shaped members with respect to saidtubes.

3. A heat exchanger as claimed in claim 1, said helical screw-shapedmembers including each a plurality of sections forming a series andbeing separated from one another by gaps.

4. A heat exchanger as claimed in claim 1, a ringshaped memberoperatively connected with said revolving part of said distributingdevice, and driving means for imparting a revolving movement to saidring-shaped member about the axis thereof and to said revolving part ofsaid distributing device operatively connected with said ring-shapedmember.

5. A heat exchanger as claimed in claim 4, said ringshaped member havingat least one projection imparting revolving movements to said helicalscrew-shaped members with respect to said tubes.

6. A heat exchanger as claimed in claim 5, said projections beingarranged for imparting to said helical screwshaped members reciprocatingmovements.

7. A heat exchanger as claimed in claim 1, and means arranged in saidcasing for imparting to the fluid a zigzag flow in said casing beforeentering said lower chamber.

8. A heat exchanger as claimed in claim 7, and deflecting means arrangedin said chamber, said deflecting means deflecting the fluid afterflowing in the zigzag flow imparted by said imparting means, into saidvertical tubes in counterflow to the solid granular material passingthrough said vertical tubes.

9. A heat exchanger as claimed in claim 1, said vertical tubesconsisting of a ceramic material.

10. A heat exchanger as claimed in claim 1, said helical screw-shapedmembers being designed as multiple screws.

11. A heat exchanger as defined in claim 4, said driving means beingadapted to impart revolving movement at different speeds to saidring-shaped member.

References Cited in the file of this patent UNITED STATES PATENTS322,257 Chase July 14, 1885 804,876 Noxon Nov. 21, 1905 969,484 KoeglerSept. 6, 1910 1,322,428 Gloess Nov. 18, 1919 1,482,812 Roberts Feb. 5,1924 1,545,596 Olney July 14, 1925 1,621,651 Bauer Mar. 22, 1927 FOREIGNPATENTS 872,215 France Sept. 21, 1940

